Securities - Unrealized Loss Positions (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 3,074	$ 16,932
Less than 12 months, Unrealized Loss	(22)	(163)
12 months or more, Fair Value	2,967	4,900
12 months or more, Unrealized Loss	(23)	(53)
Fair Value, Total	6,041	21,832
Total Unrealized Loss	(45)	(216)
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	493	495
Less than 12 months, Unrealized Loss	(8)	(5)
Fair Value, Total	493	495
Total Unrealized Loss	(8)	(5)
US Government Agencies
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	1,511	13,871
Less than 12 months, Unrealized Loss	(7)	(141)
12 months or more, Fair Value	2,344	1,619
12 months or more, Unrealized Loss	(21)	(15)
Fair Value, Total	3,855	15,490
Total Unrealized Loss	(28)	(156)
State and Municipal Obligations
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	1,070	2,566
Less than 12 months, Unrealized Loss	(7)	(17)
12 months or more, Fair Value	623	3,281
12 months or more, Unrealized Loss	(2)	(38)
Fair Value, Total	1,693	5,847
Total Unrealized Loss	$ (9)	$ (55)